OF SALTS IN ETHYL ALCOHOL AND WATER. 



93 



The third conclusion may be disposed of first as of little value, since 

 it will be remembered that salts of the alkali metals are very little 

 hydrated or alcoholated. 



We have just seen, from a study of the viscosity data, that there is a 

 marked negative viscosity, i. e., positive fluidity, at the water end of 

 the fluidity curves. On the other hand, there is a steadily increasing 

 viscosity at the alcohol end. Moreover, the transition-point from 

 positive to negative viscosity was shown to be nearer the pure water 

 than the pure alcohol. To recapitulate, it was concluded from these 



lo 







10 20 30 40 50 60 70 80 90 100 

 Percentage alcohol 



FIG. 41. N/128 Nal. 



10 20 30 40 50 60 70 80 90 100 

 Percentage alcohol 



FIG. 42. N/32 Nal. 



results that the change in association brought about by the mixing of 

 the two solvents appeared to take place more largely in the case of the 

 water than of the alcohol. 



Both our first and second conclusions, with regard to the phenomenon 

 observed in the case of conductivity, appear, then, to be in perfect 

 harmony with those concerning the association and the viscosity. As 

 to the final conclusion, it obviously follows as a matter of course from 

 what has preceded, since the association and viscosity are so closely 

 related. 



The decrease in the conductivity as a whole is more rapid for the 

 potassium iodide than for the sodium iodide. This is what might have 

 been expected from a study of the viscosity data, which, in turn, are 

 affected by the relative ionic volumes of potassium and sodium. The 

 former, having the larger volume, would have a greater negative effect 



